Edwin t



HTTEST. YE/VTOF'I (No Model.)

B. T. GREENFIELD. INSULATING JOINT FOR GONDUIT TUBES.

Patented 001;. 27-, 1896;

UNIT D STATES PATENT OFFIcE.

EDWIN T. GREENFIELD, OF NEWV YORK, N. Y., ASSIGNOR TO THE INTERIOR OONDUIT AND INSULATION COMPANY, OF SAME PLACE.

INSULATING-JOINT FOR CONDUlT-TUBES.

SPECIFICATION forming part of Letters Patent No. 570,170, dated October 27, 1896.

Application filed July 25, 1896- To all whom it may concern:

Be it known that I, EDWIN T. GREENFIELD, a citizen of the United States, residing at New York, in the county of New York and State of New York, have made a new and useful Improvement in Insulating-Joints for Conduit-Tubes, of which the following is a specification.

My invention has for its. objects, first, the

To construction of a perfect insulating-joint between adjoining conduit-tubes; second, the provision of means for firmly holding adjoining conduit-tubes securely together end to end. These objects are accomplished by the means hereinafter described, and illustrated in the accompanying drawings, in Which Figure 1 is an enlarged longitudinal sectional View of a pair of subway or conduit tubes provided with my improved insulatingjoint and means for uniting the ends of said conduit-tubes firmly together. Fig. 2 is an enlarged end view of one of the tubes and its coupling-joint shown in Fig. 1 as seen looking at the ends thereof before said tubes are 2 5 joined together.

Referring now to the drawings in detail, P represents a paper or analogous insulatingtube surrounded by an armor P, of metal.

0 0 represent cup-shaped locking-collars 0 secured to the ends of said tubes by indenting the same in grooves S S in the inner surfaces of the collars before the lining-tubes P P are inserted in position. These cup-shaped collars O O are provided with lugs or cars for 3 5 the reception of bolts B B.

F F and G G represent semicircular openings in the outer faces of the locking-collars O O, the opening F being adapted, when the collars are placed face to face, to constitute a means for pouring into the cylindrical or annular space between the collars a liquid insulating material, such as asphalt, the openings G G being for venting purposes.

T represents an annulus or ring of prepared paper or other insulating material adapted to fit snugly over the adjoining ends of the projecting paper or insulating tubes P P, said adjoining ends projecting, as clearly shown in Fig. 1, slightly beyond the ends of the armor-tubes P P. In using my improved joint the armored tubes P P P P are placed end Serial No. 600,571. (No model.)

to end, so that the bolt-holes of the lockingcollars C C are in alinement and so that the openings F F and G G are locatedat the upper or top side when in position. '55

The annulus or ring T is placed in position over one of the armored tubes, and said tubes are drawn together into the position shown in Fig. 1 by means of the bolts 13 B. After they are thus firmly secured the annular space around the annulus T and the ends of the tubes P P P P is filled with liquid insulating material, such as hot asphalt, by pouring the same through the filling-opening F, the openings G G constituting vent-openings for the escape of any air confined in the open space between the locking-collars.

It will be readily understood that with such an arrangement not only is the joint between the abutting ends of the tubes made watertight, but additional surety is given thereto by reason of the presence of the hot or molten asphalt which surrounds the annulus or collar T and the ends of the adjoining tubes, and which, in effect, when cooled, causes said ,7 5 parts to be united together into one common a mass.

Having thus described my invention, What I claim, and desire to secure by Letters Patent of the United States, is

1. As a means of uniting two or more conduit-tubes a pair of collars provided with locking-bolts, said collars being so constructed as to constitute, when joined, an annular chamber around the ends of the tubes, in combina- 8 5 tion with an insulating annulus or ring which surrounds the ends of said tubes, and a mass of insulating material which fills the aforesaid annular chamber, substantially as described.

more openings for admittingmolten or liquid insulating material into the annular chamber which surrounds'the ends of the'adjoining tubes, in combination with means for joining' said collars together substantially as described.

In testimony whereof I have hereunto subscribed my name this 30th day of June, 1896.

EDXVIN T. GREENFIELD. Vitnesses G. J. KILTNER, M. M. RoBINsoN. 

